1. Field of the Invention
The present general inventive concept relates to a peripheral component interconnect express (PCI-E) signal transmission apparatus, and an image forming apparatus using the same. More particularly, the present general inventive concept relates to a PCI-E signal transmission apparatus capable of transmitting a signal using an inexpensive cable at a high speed, and an image forming apparatus using the same.
2. Description of the Related Art
Many apparatuses and peripheral devices which are currently used are connected to a main control system so that they may operate with a wider bandwidth and greater extension capability. Conventionally, a parallel signal transmission scheme is used to connect apparatuses and peripheral devices to a main control system. However, the parallel signal transmission scheme causes a decrease in performance of the system due to a low transmission rate.
To overcome such limitations of the parallel signal transmission scheme, the data transmitting scheme has been changed from the parallel signal transmission scheme to a serial signal transmission scheme, and a peripheral component interconnect express (PCI-E) based scheme for transmitting a signal at a high speed has been used in which a bus width is reduced and the data transmission rate is increased. Use of the PCI-E based scheme makes a complicated process of computer-aided design (CAD) routing simple, and increases the data transmission rate.
In more detail, to transmit a signal using the PCI-E based scheme, an expensive PCI-E external cable and a connector suitable for the PCI-E external cable are required. In this situation, the PCI-E external cable needs to be connected to an apparatus via a connection path which is formed on the outside of the apparatus, so if the PCI-E external cable is connected to the apparatus, the PCI-E external cable protrudes from the apparatus. Additionally, if the PCI-E external cable is inserted into the apparatus, the PCI-E external cable is too thick to be fitted in the apparatus.
Furthermore, the PCI-E external cable comprises 18 pins in total. Among 18 pins, pins corresponding to pair signals Tx and Rx and three to four GND pins are used to transmit signals. In other words, as only seven to eight pins of the 18 pins are used to transmit signals, less than 50% of the signal line is actually used.
As described above, when the PCI-E based scheme is used, a signal is able to be transmitted at a high speed as compared to the conventional parallel signal transmission scheme, but many problems may occur. In more detail, the PCI-E based scheme requires an expensive PCI-E external cable and a connector, and sets a connection path to the outside of an apparatus. Additionally, it is difficult to fix the PCI-E external cable and secure space, and signal lines are wasted. Therefore, there is a need for methods to solve these problems while maintaining the advantages of the PCI-E based scheme.